Flora of New Zealand Series

shore groundsel

Prostrate to ascending, or erect, annual or short-lived perennial herb. Lvs glabrous or sparsely hairy, cuneately narrowed at base and often appearing petiolate, narrow-ovate, elliptic, oblong, or lanceolate, not lobed and entire, irregularly pinnately toothed, or lobed with many lvs usually pinnatifid with narrow to broad, entire or few-toothed, usually distant segments, 15-65-(110) × (3)-5-15-(60) mm; primary segments, lobes, or teeth (0)-3-6-(7) on each side. Uppermost lvs smaller, less divided, often amplexicaul. Supplementary bracts 6-16, 1-3 mm long. Involucral bracts (8)-10-13-(15), 4-6.5 mm long, usually glabrous, sometimes with a few scattered hairs. Ray florets 7-13 (extremely rarely 0); ligules yellow, (1)-2-7-(9) mm long. Disc yellow, 3-6 mm diam. Achenes usually densely hairy only between ribs, very rarely glabrous or ± evenly hairy, slightly narrowed to apex, 2.2-3 mm long.

N.: throughout, mainly coastal, occasional inland; S.: coastal Marlborough, Nelson, Westland (N. of Greymouth) and Canterbury S. to Rakaia R. ( var. lautus); K. ( var. esperensis Sykes), Ch. ( var. lautus).

Possibly also indigenous to Australia.

Coastal cliffs, turf, sand and rocks.

FL Jan-Dec.

Plants of S. lautus var. lautus are distinguished from related spp. as follows: from S. radiolatus by smaller size, usually fewer involucral bracts, and absence of lanate hairs, from S. sterquilinus by smaller size and fewer involucral bracts, from S. skirrhodon by fewer involucral bracts and more divided lvs, from S. glaucophyllus by the annual to short-lived perennial habit and the irregular lf division with fewer more distant teeth or segments, and from S. carnosulus by the smaller capitula and narrower lf segments. Ornduff (op. cit.) accepted 2 subspp. for S. lautus in N.Z. and considered that the name S. lautus is not applicable to any Australian plant; subsp. carnosulus (Kirk) Ornd. is treated here at sp. rank as S. carnosulus. Sykes, W. R., New Zealand J. Bot. 9 : 533-538 (1971), described plants from K. as var. esperensis; they differ from var. lautus mainly in the lvs which are never deeply pinnatifid. Ali (1964, op. cit.) regarded N.Z. and Australian plants as only subspecifically distinct. Fortunately, S. lautus was described from N.Z. and so the taxonomy of Australian plants only affects the naming of N.Z. material to the extent that both N.Z. vars must be referred to subsp. lautus if Ali's treatment is accepted.

Some collections from Cuvier Id (e.g., CHR 132999, Atkinson, 15.6.1970; AK 10584, Cheeseman, Oct. 1895) differ from typical S. lautus in the more erect habit, more dissected lvs densely hispid on the lower surface, and the long narrow capitula with short rays. Such plants have a chromosome number of 2 n = 100. Some plants from the Mokohinau Is (e.g., AKU 16141, Cameron 2752, 6.1.1984; AK 165147, Wright 6220, 5.1.1984) are similar but are almost glabrous and have slightly shorter capitula. In other floral characters and lf shape, plants from these 2 localities fall within the range exhibited by mainland S. lautus, so that although the Cuvier plants appear very distinctive it seems unwise to accord them taxonomic recognition without fuller study. More typical forms of S. lautus have also been collected from both localities.